Exhibit 12.1

Ameren Corporation

Computation of Ratio of Earnings to Fixed Charges

(Thousands of Dollars, Except Ratios)



|                                                                                     |  |                         |         |   |      |   |         |      |  |   |           |   |  |      |           |   |  |   |           |  
|------------------------------------------------------------------------------------ |  | ----------------------- | ------- | - | ---- | - | ------- | ---- |  | - | --------- | - |  | ---- | --------- | - |  | - | --------- | -
|                                                                                     |  | Year Ended December 31, |        
|                                                                                     |  | 2001                    |         |   | 2002 |   |         | 2003 |  |   | 2004      |   |  | 2005 |          
|Net income from continuing operations                                                |  | $                       | 468,545 |   |      | $ | 382,065 |      |  | $ | 524,145   |   |  | $    | 529,884   |   |  | $ | 605,725   |  
|Less- Change in accounting principle                                                 |  |                         | (6,841  | ) |      |   | -       |      |  |   | 18,416    |   |  |      | -         |   |  |   | (22,135   | )
|Less- Minority interest                                                              |  |                         | (4,252  | ) |      |   | (13,627 | )    |  |   | (7,050    | ) |  |      | (4,201    | ) |  |   | (3,231    | )
|Add- Taxes based on income                                                           |  |                         | 305,667 |   |      |   | 236,320 |      |  |   | 301,209   |   |  |      | 282,558   |   |  |   | 356,016   |  
|                                                                                     |  |                         |         |   |      |   |         |      |  |   |           |   |  |      |           |   |  |   |           |  
|Net income before income taxes, change in accounting principle and minority interest |  |                         | 785,305 |   |      |   | 632,012 |      |  |   | 813,988   |   |  |      | 816,643   |   |  |   | 987,107   |  
|                                                                                     |  |                         |         |   |     
|Add- fixed charges:                                                                  |  |                         |         |   |      |   |         |      |  |   |           |   |  |      |           |   |  |   |           |  
|Interest on long term debt                                                           |  |                         | 193,163 |   |      |   | 210,481 |      |  |   | 271,525   |   |  |      | 269,868   |   |  |   | 297,822   |  
|Estimated interest cost within rental expense                                        |  |                         | 3,576   |   |      |   | 2,852   |      |  |   | 4,169     |   |  |      | 3,185     |   |  |   | 4,208     |  
|Amortization of net debt premium, discount, and expenses                             |  |                         | 5,485   |   |      |   | 8,260   |      |  |   | 10,210    |   |  |      | 12,983    |   |  |   | 14,687    |  
|Subsidiary preferred stock dividends                                                 |  |                         | 12,445  |   |      |   | 10,841  |      |  |   | 10,861    |   |  |      | 11,089    |   |  |   | 12,745    |  
|Adjust preferred stock dividends to pre-tax basis                                    |  |                         | 8,002   |   |      |   | 6,706   |      |  |   | 6,469     |   |  |      | 5,913     |   |  |   | 7,227     |  
|                                                                                     |  |                         |         |   |      |   |         |      |  |   |           |   |  |      |           |   |  |   |           |  
|Total fixed charges                                                                  |  |                         | 222,671 |   |      |   | 239,140 |      |  |   | 303,234   |   |  |      | 303,038   |   |  |   | 336,689   |  
|                                                                                     |  |                         |         |   |      |   |         |      |  |   |           |   |  |      |           |   |  |   |           |  
|Less: Adjustment of preferred stock dividends to pre-tax basis                       |  |                         | 8,002   |   |      |   | 6,706   |      |  |   | 6,469     |   |  |      | 5,913     |   |  |   | 7,227     |  
|                                                                                     |  |                         |         |   |      |   |         |      |  |   |           |   |  |      |           |   |  |   |           |  
|Earnings available for fixed charges                                                 |  |                         | 999,974 |   |      |   | 864,446 |      |  |   | 1,110,753 |   |  |      | 1,113,768 |   |  |   | 1,316,569 |  
|                                                                                     |  |                         |         |   |      |   |         |      |  |   |           |   |  |      |           |   |  |   |           |  
|Ratio of earnings to fixed charges                                                   |  |                         | 4.49    |   |      |   | 3.61    |      |  |   | 3.66      |   |  |      | 3.67      |   |  |   | 3.91      |  
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